Green Spoon Worm

Metabonellia haswelli (Johnston & Tiegs)

Taxonomy

Scientific Details

Family level description.Members of Bonellidae (and related families of spoon worms) are soft bodied sac-like worms with a very long extensible proboscis. There is no external evidence of segmentation. They have a dark green pigment and if handled live will temporarily stain fingers.

Species level technical description.Body dark green with paler warty swellings. Two ventral chaetae just posterior to the mouth, but these are difficult to see except in dissection. Proboscis forked, terminal arms shorter than stem.

Taxonomy

Phylum:

Annelida

Class:

Polychaeta

Order:

Unplaced

Family:

Unplaced

Genus:

Metabonellia

Species:

haswelli

General Description

In members of this genus the proboscis is forked, with the terminal branches shorter than the basal part (other spoon worms in this part of Australia have unbranched proboscis). Body up to about 8 cm long.

Biology

Spoon worms were previously classified in their own Phylum: Echiura. However, recent DNA studies have shown that these worms are modified polychaetes with very reduced chaetae and segmentation and they are now grouped in the Phylum Annelida.